So, you want to download a previous version of a mod, but it has been archived or a file you wanted have been archived. Worry not. I will go through the process and explain (with pictures) exactly how you can download archived files. This guide works exactly the same for Fallout 4 mods and every other archived mods on this site, I would presume. I have only tested it for fallout 4 and Skyrim.
For this guide I'm going to use Universal (SKSE) Rim Lighting Fix since it's convenient, and it already has an archived file.
First go to the files section, right-click on mod manager download or manual download, then click on open link in a new tab (or something similar). 
Your page will then look like this.
copy the text in your search bar, it's very important since you are going to use it later. Open a new tab and paste it in the search bar of that tab.
now go back and click on file archive
Right click anywhere on the page (you can just click where the red dot is) and choose to inspect the page. For this section, I'm gonna offer pictures for Firefox browser and Google Chrome. If you use any other browser, then you are on your own. This part is for Firefox.
Your page should look something like this now. Write data-id in the highlighted field and press enter. Press enter until you see this long line. On the long line you can see the numbers you will copy, file name and version. The version of this file is 1.0.0. If you are ever unsure if you have found the right file, you can look at the version number.
copy the numbers in the highlighted area. The ones for this mod is, 500740. Only copy the numbers, not the other symbols.
This is for Google Chrome.
Right click anywhere on the page (you can just click where the red dot is) and choose to inspect the page. Make sure to read the Firefox part too, it has some info not written for this part.
Your page should look something like this now. Click on the 3 dots in the corner and then on search.
write data-id in the search field and click enter. You can drag the inspect window to make it bigger if you have trouble seeing the long highlighted line. Just start dragging where the arrow points. Scroll up to the last picture in the Firefox part.
Now go to the tab you previously opened, highlight these numbers and paste the numbers you just copied so it goes from the 1st picture to the second.
Press enter and now your page will look like this. The highlighted field is the version number. Congratulations, you have just learned how to download archived files on nexus.
If you have questions, just ask. I can't guarantee I can help, though. I just learned how to do this today.
Feel free to share/post this guide on other sites. It would be nice if you give me credit for the guide, but it's not required. What matters most is that more people can learn how to download archived mods.
28 comments
Edit: i dimply pasted the file id code on the address bar, swapping the archived file code with the legit new one and pressed enter. Old methods still work ;)
But when I went to roll back, the previous version was archived.
You're a god-send. Thank you.
The Nexus should really just add a button for downloading, which has a pop-up stating it's an old unsupported version before it lets you download it.
THANK YOU!